溶液pH及电流浓度对电化学法生成羟基自由基降解机制的影响

用电化学稳态极化曲线分析方法讨论了溶液pH值及电流浓度对染料降解脱色的影响.实验结果表明,pH值将影响着阴极反应的方向、电极电位与染料降解脱色的效果.在酸性溶液中有利于过氧化氢的生成,阴极电位较低,但不利于随后的絮凝步骤;在中性溶液中染料降解脱色的综合效果较好,COD_Cr去除率可达80%以上.文中还讨论了电流浓度对降解脱色效果的影响,当电解槽内电流浓度达0.5 A/L时可取得满意的效果,电流浓度太大时,体系将伴随着析出氢气等的副反应,降解反应的电流效率下降.      

在Suwannee河富里酸溶液中扑热息痛的光解行为

以中压汞灯为光源模拟阳光,研究了扑热息痛(ACT)在Suwannee河富里酸(SRFA)溶液中的光解行为,探讨了不同浓度的腐殖质、ACT、硝酸盐、碳酸盐、二价铁离子和pH值对ACT光解的影响,采用GC/MS技术鉴定了ACT的光解产物,并探讨其在腐殖质体系中可能的光解途径.结果表明,增加溶液中的腐殖质、硝酸盐、二价铁离子浓度和pH值能促进ACT的光解,而增加水体中的ACT和碳酸盐浓度则会抑制ACT的光解.     

壳聚糖吸附废水中铅离子的研究

研究了壳聚糖对废水中Pb2+的吸附特性,考察了壳聚糖溶液加入量、吸附时间及体系pH等条件对壳聚糖吸附溶液中Pb2+效果的影响。当质量分数为0.8%的壳聚糖溶液加入量为0.4 mL、吸附时间为30 m in、体系pH为5~6时,处理浓度为1×10-4mol/L的含Pb2+溶液,Pb2+去除率可达98%;同样条件处理印染废水,Pb2+去除率可达92.6%。     

垃圾焚烧飞灰熔融过程中重金属的固化机理以及熔渣浸出特性的研究

研究了中国垃圾焚烧飞灰中主要重金属在熔融过程的固定化机理,定义了固定率这个参数来表征此过程。采用了中国和美国的危险废物浸出毒性鉴别方法来判别飞灰及其熔融渣的浸出毒性。研究结果表明,固定率能够较好地表征重金属在熔融过程不同温度阶段的固定情况;按照中国和美国废物浸出毒性鉴别标准,飞灰熔融处理后的熔渣不属于危险废物,具备资源化利用的条件。     

可持续发展视角下的城镇化与都市化抉择——基于国际生态足迹面板数据实证研究

在人口众多、人均资源匮乏、生态环境脆弱的中国,都市化与中小城镇化何种城市化模式更符合可持续发展的要求,存在争议。通过对中国、美国、加拿大、英国、法国、日本、意大利、澳大利亚、韩国、巴西、印度、墨西哥、南非等发达国家与主要发展中国家的生态足迹、生态承载力、城镇人口比重等宏观面板数据的计量分析,揭示城市化客观规律,并与中国实际结合。研究表明:其一,百万以上人口城市的都市化更符合生态资源的可持续性。其显著降低人均生态足迹与生态环境压力,并倾向于增加人均生态承载力。如此促进生态资源的供给,削减生态资源的人均需求而有利于可持续发展。其二,百万以下人口城市的中小城镇化显著增加生态足迹与生态环境压力。其布局结构松散,倾向于占用大量生态环境资源,减少生态承载力供给;而低效、分散、粗放的生产生活方式也增加生态足迹,总体不利可持续发展。其三,人均固定资本存量、人均储蓄、政府购买都对可持续发展具有潜在的促进作用。最后,建议中国推行都市化战略,充分发挥大都市的规模经济效应,提高生态环境资源的利用效率;适度限制城镇化,避免中小城镇遍地开花对资源环境造成显著危害;学习国际优秀城市化经验及相关配套制度,并与中国结合;注重技术创新,发挥高新科技及资本带来的生产方式改进与效率提升。     

汞矿区周边农田土壤微生物群落结构特征及其环境驱动因子

为探究汞矿区周边农田土壤微生物群落结构特征及其与环境驱动因子关系,以铜仁汞（Hg）矿区周边（碧江区坝黄镇、石阡县花桥镇、江口县凯德镇和碧江区川硐镇,分别用BJ、SQ、JK和TR表示）农田土壤为研究对象,分析了土壤理化性质、Hg污染状况、酶活性以及微生物群落结构特征.采用冗余分析（RDA）和相关性网络分析了土壤微生物群落结构与环境因子互作关系.结果表明,研究区土壤存在一定程度的Hg污染,其中,JK和TR属于轻度污染,SQ和BJ属于偏中度污染;TR存在中等潜在生态风险,BJ和JK存在强潜在生态风险,SQ存在很强潜在生态风险.研究区土壤的主要细菌优势菌群包括：变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、酸杆菌门（Acidobacteria）和绿弯菌门（Chloroflexi）;主要真菌优势菌群包括：子囊菌门（Ascomycota）、担子菌门（Basidiomycota）和被孢霉门（Mortierellomycota）.RDA分析表明,pH、蔗糖酶（SC）和过氧化氢酶（CAT）活性是土壤细菌群落结构组成的主要环境因子,pH、碱解氮（AN）、速效钾（AK）、HCl-Hg、酸性磷酸酶（ACP）和脲酶（URE）活性是土壤真菌群落结构组成的主要环境因子.相关性网络分析表明,pH、AP、HCl-Hg、SC、ACP和CAT是影响土壤Proteobacteria、Acidobacteria、Actinobacteria、Chloroflexi、厚壁菌门（Firmicutes）、棒状杆菌门（Rokubacteria）和浮霉菌门（Planctomycetes）等细菌群落结构的主要环境因子;而AK、pH、TN、AP、AN、ACP、URE和SC活性是影响土壤Ascomycota、Basidiomycota、Mortierellomycota、球囊菌门（Glomeromycota）、壶菌门（Chytridiomycota）、红藻门（Rozellomycota）、梳霉门（Kickxellomycota）和Mucoromycota （毛霉门）等真菌群落结构的主要环境因子.     

国内外空气质量模型研究进展

本文系统总结了国内外空气质量模型的发展历程及最新进展,分析不同时期、不同类别空气质量模型的基本特征及适用条件,重点介绍ISC3、AERMOD、ADMS、CALPUFF四个法规化中小尺度空气质量模型及NAQPMS、WRF-CHEM、CAMx、CMAQ四个综合型区域尺度空气质量模型的基本原理及典型特征,探讨空气质量模型在我国实践应用中存在的主要问题。最后分析我国建设法规化空气质量模型的必要性,并提出法规化模型建设的前置条件及核心内容。     

Effect of bulk density of coking coal on swelling pressure

Coking coals are the important raw materials for the iron and steel industries and play an important role on its sustainable development, especially on the stamp-charging coke making with the characteristics of increasing the bulk density. There is a significance on the reasonable usage of the coking coal resource with the reduced production cost, improved efficiency of the economy to develop the stamp-charging coke making technology. Important effects of the density of coking coal on the coking and caking properties were investigated. In the article, the maximum values of swelling pressure and variation of Laowan gas coal and Xinjian 1/3 coking coal, Longhu fat coal and Didao coking coal, which were mined at Shenyang and Qitaihe respectively, were investigated under different bulk densities during the coking. The results showed that when the values of density increased from 0.85 ton/m³ to 1.05 ton/m³, for the Laowan gas coal, swelling pressure variation and even the maximum value changed slightly. The swelling pressure was 3.63 KPa when the density was improved to 1.05 ton/m³; for the Xinjian 1/3 coking coal, the values of swelling pressure changed significantly and the maximum values was 82.88 KPa with the density improved to 1.05 when the coal was heated to 600℃. The coke porosity, which was investigated by automatic microphotometer, decreased from 47.4% to 33.1% with the increasing of the density from 0.85 ton/m³ to 1.05 ton/m³, and the decreased value was 14.3%. Meanwhile, the pore structures of four cokes were characterized by an optical microscope.     

Effect of bulk density of coking coal on swelling pressure

Coking coals are the important raw materials for the iron and steel industries and play an important role on its sustainable development, especially on the stamp-charging coke making with the characteristics of increasing the bulk density. There is a significance on the reasonable usage of the coking coal resource with the reduced production cost, improved efficiency of the economy to develop the stamp-charging coke making technology. Important effects of the density of coking coal on the coking and caking properties were investigated. In the article, the maximum values of swelling pressure and variation of Laowan gas coal and Xinjian 1/3 coking coal, Longhu fat coal and Didao coking coal, which were mined at Shenyang and Qitaihe respectively, were investigated under different bulk densities during the coking. The results showed that when the values of density increased from 0.85 ton/m³ to 1.05 ton/m³, for the Laowan gas coal, swelling pressure variation and even the maximum value changed slightly. The swelling pressure was 3.63 KPa when the density was improved to 1.05 ton/m³; for the Xinjian 1/3 coking coal, the values of swelling pressure changed significantly and the maximum values was 82.88 KPa with the density improved to 1.05 when the coal was heated to 600°C. The coke porosity, which was investigated by automatic microphotometer, decreased from 47.4% to 33.1% with the increasing of the density from 0.85 ton/m³ to 1.05 ton/m³, and the decreased value was 14.3%. Meanwhile, the pore structures of four cokes were characterized by an optical microscope.     

火化烟气中二噁英类排放特征及其对周边环境影响研究

文章对国内不同地区8台无后处理设备和2台带有后处理设备的火化炉烟气中二噁英类的排放情况进行了研究。结果表明,8组未经后处理的烟气中二噁英类浓度范围为52.01～332.97 ng/m3,总二噁英类毒性当量浓度范围为:1.27～5.14 ng TEQ/m3,2组经后处理设备的火化机烟气中二噁英类浓度分别为16.53 ng/m3,20 ng/m3,总二噁英类毒性当量浓度分别为0.39 ng TEQ/m3,0.28ng TEQ/m3,均已降低到国标要求的0.5 ng TEQ/m3限制以下。对火化烟气中二噁英类同系物的分析表明,氯代数目多的同系物浓度要低于氯代数目少的同系物浓度。此外,对4个火葬场周边土壤中二噁英浓度的测试表明,火葬场周边土壤中二噁英浓度低于多数国家对于居住地二英土壤浓度的限制。该研究为火化烟气污染治理的进一步研究奠定了基础。